Composition-filled brake-shoe.



J. D. GALLAGHER & H. JONES.

COMPOSITION FILLED BRAKE SHOE.

APPLICATION FILED JULY 2,1912.

Patented Dec. 23, 1913.

I In ven ors .of cast malleable iron.

UNITED STATES PATENT OFFICE.

JOSEPH D. GALLAGHER, OF GLEN RIDGE, NEW JERSEY, AND HARRY JONES, OF SUF- I FERN, NEW YORK, ASSIGNORS, BY MESNE ASSIGNMENTS, TO AMERICAN BRAKE SHOE & FOUNDRY COMPANY, OF MAHWAH, NEW JERSEY, A CORPORATION OF NEW JERSEY.

COMPOSITION-FILLED BRAKE-SHOE.

Specification of Letters Patent.

Application filed July 2, 1912.

To all whom it may concern Be it known that we, Josnrn D. GALLA- GHER, a citizen of the United States, and a resident of Glen Ridge, county of Essex, and State of New Jersey, and HARRY Jones, a citizen of the United States, and a resident of Suffern, in the county of Rockland and State of New York, have made and invented certain new and useful Improvements in Composition-Filled Brake-Shoes, of which the following is a specification.

Our invention relates to an improvement in brake shoes, and more particularly to that kind or type usually known and referred to as filled shoes, and wherein is employed a casing for containing a composition body. Heretofore, it has been deemed advisable to construct this containing shell or casing .of a ductile metal such as malleable iron,

wrought iron, or steel, and in some instances From numerous ex periments, however, we have found that by so doing, the action of the wheel upon the shoe tends to heat the edges of the shell and cause the metal to spread or flow, and thus to a certain extent reduce the area of the composition body cont-acting with the wheel. Furthermore, the extreme heat hardens or tempers the edges of the shell, causing the latter to cut and score the wheel tread, and in .ome instances burn the particles of metal forming the edges of the shell, which becoming detached, also assist in scoring and injuring the tread of the wheel. In order to avoid these objections, we have learned from our experiments that the best results are obtained by forming the shell from a metal which, when cold, will be tough and strong, yet when heated will become extremely brittle and rapidly disintegrate when in service. To accomplish this result, we have employed iron and steel having a small amount of sulfur, and also iron or steel containing about twelve per cent.

of manganese steel. These metals we have found sufficiently strong when in a cold state to withstand any strains that might be imposed upon them while filling the same with the composition to form the body, but which when highly heated by frictional contact with the wheel, will become very brittle, and while in service rapidly disintegrate, preventing any injury to the tread of the Wheel, and at the same time permitting the entire area of the Wearing face of the composit on body to contact with thewheel.

It 1s of course to be understood that we do not in any wise limit our invention to the use of the above metals or any alloys of the same, as doubtless many others might be utilized to accomplish the same result and which contain the characteristics above mentioned, viz., toughness and strength while cold, and extreme brittleness when heated, and which while heated, will rapidly disintegrate or crumble in service, and hence our claims are intended to broadly cover a composition or filled brake shoe wherein the casing containing the composition body is made from a metal having the characteristics above mentioned.

In the drawing accompanying and forming a part of this application: Figure 1 is a view showing a section upon a longitudinal central plane of a brake shoe of the type to which our invention relates; and, Fig. 2 is a view showing a section of the same upon a transverse plane indicated by the lin'e 2 2, Fig. 1.

Referring to the drawing, the external metallic shell or casing, designated by the reference character 3, may be made from steel containing about 12 per cent. o-f'niair ganese, the shell being preferably formed from sheet metal having a thickness of about to by means of suitable forming dies. The shell 3 contains a filler 4, that is, a substance the character of which is essentially non-metallic, although the same may contain a metal such as iron in a finely divided form, for example, in the form of chips or borings, as an. ingredient. Strips or blocks of metal are also sometimes embedded in the material, but in mostcases it is preferable that the filler be non-metallic. The filling contained within the shell may be of various materials, or may be composed of various ingredients. a composition made up of the following ingredients with which we have secured satisfactory results;

Fire clay ,1 part Iron borings 3 parts Crushed iron ore; 3 parts Coal tar 1 part Asphalt a part the ingredients being thoroughly mixed and We recommend, however,

heated to about 112 F. and pressed into the casing.

When a brake shoe, formed as above explained, is put into service, substantially the entire braking effect thereof is due to the composition filling. The edges of the shell, however, contacting with the tread of the wheel, are heated to such a degree that the metal will lose the qualities of toughness and ductility possessed by it when cold, and will become extremely brittle, and in such state rapidly disintegrates when the shoe is in service, thus preventing a flow of metal and the formation of a serrated or feathered edge, as is the case with the metals hereto fore employed for this purpose.

It will be understood that the basic metal of the shell above referred to is preferably iron, and that the property by virtue of which it becomes brittle at high temperatures, and rapidly disintegrates in service, is due to the manganese associated therewith. As before suggested, we have also found that good results may also be obtained with a metal such as iron or steel containing a. small amount of sulfur, and undoubtedly like results may also be obtained by various other mixtures or alloys, it being necessary only that the metal be of such a character that when cold it may be sufliciently strong to withstand anystrains imposed upon it while being filled with the composition body, or while being handled or transported, the casing itself being employed solely for the purpose of receiving and holdin the body or wearing portion, and not for t e purpose of assisting.the composition body in the braking or frictional qualities; and to become brittle when heated to permit of the rapid disintegration of the casing during thev Letters Patent:

1. A brake shoe comprising a shell made from metal possessing the characteristics of being tough and strong while cold, and extremely brittle when heated, so that said shell will rapidly disintegrate while in service, and a filler contained within said shell.

2. A brake shoe comprising a composition wearing body, and a shell containing said body, said shell being made from material possessing the characteristics of bein tough and stron while cold, andextreme y brittle when heated, and which said shell will therefore rapidly disintegrate while the shoe is in service,

3. A brake shoe comprising a composition wearing body, and a shell containing said body, said shell being made from an alloy of metal containin manganese, whereby said shell when co d will betough and strong, and extremely brittle when heated,

and which will therefore rapidly disintegrate while the shoe is in service.

Signed at New York, in the county of New York, and. State of New York, this 27th day of June, 1912.

JOSEPH D. GALLAGHER. HARRY JONES.

Witnesses A. V. WALSH, MARY B. J UsncE. 

